Drones and their use in agriculture

There are currently various projects under way involving the commercial use of drones; for example, Amazon wants to deliver parcels to people's doorsteps in the US using drones

There are currently various projects under way involving the commercial use of drones; for example, Amazon wants to deliver parcels to people's doorsteps in the US using drones. Germany has the ‘Dönercopter’, a small drone that delivers kebabs. In Australia, Zookal and Flirtey use them to deliver books, while in London the Yo Sushi restaurant chain is testing drones that carry trays from the kitchen directly to customers' tables outside the restaurant.

WHAT ARE DRONES?
An unmanned aerial vehicle — UAV — or unmanned aerial system — UAS — is known in Spanish by the acronym VANT and as a drone.
They are equipped with state-of-the-art equipment such as GPS, infrared sensors, high-resolution cameras and radar controls. Drones can send detailed information to satellites, which then relay it to ground control, all within milliseconds.
A UAV system has two clearly defined segments:

• Flight segment: comprising the aerial vehicle and recovery systems (landing on wheels or skids, net, cable, parachute, etc.).
• Ground segment: comprising the control station (on the ground, receiving information sent by drones and issuing commands in return) and launch systems (which may be hydraulic, pneumatic, etc.).

USES OF DRONES
In the civilian sphere, UAVs are used in different sectors, such as:

• Infrastructure inspection
• Surveying
• Risk and natural disaster management (fires, etc.)
• Exploration of hard-to-reach places: caves, cliffs, etc.
• Monitoring wind energy systems
• Filmmaking and sports photography
• Environmental monitoring
• Locating shoals of fish
• Hunting and game management
• Wildlife research
• Media and entertainment
• Mobility and traffic
• Crowd monitoring and analysis: demonstrations, concerts, etc.
• Agriculture

USE IN AGRICULTURE
Alongside public safety, one of the applications with the greatest potential is precision agriculture and field monitoring. This is highlighted in the study The Economic Impact of Unmanned Aerial Systems Integration in the United States.
In essence, precision agriculture uses new technologies to study a plot in detail, allowing each treatment to be applied locally.
Precision agriculture began to be studied in the 1980s, but it was only from the turn of the century that technological development, and particularly inexpensive access to technology, enabled it to take off fully.
Precision agriculture offers three benefits: it reduces costs, improves crop profitability and lessens environmental impact, because agrochemical applications are targeted and adjusted to the crop's actual requirements.
Japan and Brazil are examples of countries that have used drones in agriculture for some time. In Japan, Yamaha launched an unmanned helicopter in 1991 designed to spray herbicides and fertilisers. Now known commercially as RMAX, these helicopters are hired for spraying tasks. Brazil is one of the few countries with regulations governing drone use, and they are commonly used in soya fields.
Specific agricultural applications

• Crop checks (for example, monitoring agricultural subsidies).
• Detecting water stress (insufficient irrigation) in crops to support efficient water management.
• Detecting nutritional stress in crops (optimal fertiliser use only in areas where application is needed).
• Early detection of crop diseases and pests.
• Crop quality indices (e.g. vines).
• Creating inventories of cultivated areas.
• Supervising sprayed areas.

The advantage of drones in agriculture is therefore that they provide farmers with information on crops' water status, development and health, obtained almost in real time, so that plant protection treatments, irrigation or fertilisation can be targeted at areas where these needs are detected, at precisely the right time.

EXAMPLES OF RESEARCH STUDIES
• Using UAV images to map agronomic targets
In this study, CSIC researchers investigated using drones to detect weed growth in extensive crops. Multispectral images were taken to analyse the different areas of the plot.
Using multispectral cameras means capturing not only conventional optical images but also other parts of the spectrum, with thermal or infrared cameras. Infrared makes it possible to distinguish vegetation conditions, revealing, for example, a crop's nutritional status or health. If the camera also has a thermal sensor, water stress can be determined in different crop areas. Drones can fly almost at ground level, allowing photographs with very high spatial resolution.
This application was demonstrated in maize, although it is also being used in sunflowers and wheat. The study was conducted in a maize plot infested with several broad-leaved and narrow-leaved weed species. The resulting map from the UAV images showed:

• Each weed cover category
• Classification accuracy

This detection and mapping of weeds allows treatment at the most appropriate time for the crop, avoiding delays that could result in herbicide treatment being applied at an unsuitable time.
FIELDCOPTER project
This is a collaborative project under the Eighth European Framework Programme, involving six partners from the Netherlands, Belgium and Spain, including the Advanced Centre for Aerospace Technologies (Catec) and the Spanish National Research Council (CSIC).
Current satellite imagery services in Europe cannot provide thermal images with the level of detail needed for precision agriculture applications. The project aims to combine the communications technologies of the Egnos air navigation system with the latest UAV technologies to create new applications giving users real-time information on important crop issues, such as water or irrigation monitoring and control, locating nutrient deficiencies in the soil, and identifying diseases and pests in crops.
This system will therefore enable better use of agricultural resources.
DRONE COSTS
Numerous companies already hire out or sell drones. Full-day hire can range from €1,000 to €3,000, while purchase prices range from €6,000–€8,000 up to €30,000–€40,000, depending on technology and reliability.
AIRSPACE — LEGISLATIVE FRAMEWORK
In the European Union, UAVs fall into two main legal groups, each regulated by different authorities:

• UAVs weighing more than 150 kg, governed by European Aviation Safety Agency regulations.
• UAVs weighing less than 150 kg, regulated by each Member State's civil aviation authorities.
• The roadmap for safely integrating UAVs into European airspace is expected to be ready from 2016.

Most UAVs developed so far are very small and light; those used in agriculture may weigh as little as 2–3 kg. For now, UAVs weighing less than 25 kg appear unlikely to face excessively restrictive air safety measures, because they pose little danger to the navigation of crewed aircraft.
Unlike in the US, the EU has not seen the anticipated objections to UAVs equipped with cameras and sensors regarding possible invasions of third parties' privacy.

CONCLUSIONS
• Drones represent a revolution in the civilian market. If their use in airspace is regulated favourably, they will bring a new way of understanding and conceiving many services as we know them today (parcel delivery, home food delivery, etc.).
• Precision agriculture and field monitoring are among the applications with the greatest potential.
• This new system will increase farmers' economic returns, prevent unnecessary applications of plant protection compounds (herbicides and pesticides), and reduce water consumption in fields.

USEFUL LINKS
• Association for Uncrewed Vehicle Systems International (AUVSI)
• Spanish Aviation Safety Agency (AESA)
• Advanced Centre for Aerospace Technologies
• Fieldcopter project — European Commission's Eighth Framework Programme
• Spanish Institute for Strategic Studies
• Aerotendencias
• Air navigation. Ministry of Public Works
• Institute for Sustainable Agriculture, Córdoba
• Advanced Centre for Aerospace Technologies — CATEC

Source: ELIKA – Basque Foundation for Agri-food Safety (foundation PDF document)